Good practice guide - EECA...heat pump installation Figure 2.1 Split system heat pump 8 Figure 2.2...
56
Good practice guide Heat pump installation - April 2020 Inspiring energy efficiency · advancing renewable energy
Transcript of Good practice guide - EECA...heat pump installation Figure 2.1 Split system heat pump 8 Figure 2.2...
Good practice guideHeat pump installation - April 2020Inspiring energy efficiency · advancing renewable energy
2
Contents
Index of figures and tables 5
1.0 Introduction 7
2.0 Heat pump systems 82.1 Types of heat pump systems 8
2.2 Components of a heat pump 10
2.3 How a heat pump works 12
2.4 Variable-speed (inverter) compressors 12
3.0 Heat pump performance 133.1 Heat pump efficiency 13
3.2 Energy rating label 14
3.3 Effects of temperature on efficiency and heating capacity 14
3.4 Impacts of defrost cycle on efficiency and heat output 15
4.0 Designing a heat pump system 164.1 Steps for designing a heat pump system 16
4.2 The importance of correct heat pump sizing 16
4.3 Step 1: Determine requirements 17
4.4 Step 2: Calculate heat load requirement 19
4.5 Step 3: Determine design temperature 20
4.6 Step 4: Select a system to meet requirements 21
4.7 Step 5: Locate the units 21
5.0 Toolkit 25
6.0 Installing pipework 266.1 Pipework installation 26
6.2 Pipework pre-installation in new buildings 33
7.0 Heat pump installation 357.1 Pre-installation checklist 35
7.2 Installing the indoor unit 36
7.3 Installing the outdoor unit 39
7.4 Connecting piping to indoor and outdoor units 41
7.5 Leak/pressure test 44
7.6 Evacuation of the system 44
8.0 Refrigerants 468.1 Refrigerant charging 47
8.2 Labelling as record of service 47
9.0 Electrical requirements 489.1 Installing electrical wiring 48
9.2 Outdoor unit connections 48
9.3 Nameplate 49
EECA (Energy Efficiency and Conservation Authority) has taken reasonable steps to maintain current and accurate information in this document. However, no guarantee is made as to the currency or accuracy of information.
Good practice guide to heat pump installation
3
10.0 Testing, commissioning and customer operating instructions 5010.1 Pre-commissioning checks 50
10.2 Electrical checks 50
10.3 Prepare the remote control 50
10.4 Testing the new system 51
10.5 Instructions to the owner 51
10.6 Checklist for using a heat pump efficiently 52
10.7 Quality assurance checklist for auditing 53
11.0 Servicing and maintenance 5411.1 Owner maintenance 54
11.2 Service person maintenance 55
Contents
4
Index of figures and tables
Good practice guide to heat pump installation
Figure 2.1 Split system heat pump 8
Figure 2.2 Multi-split system heat pump 8
Figure 2.3 Ducted heat pump system 8
Figure 2.4 High wall-mounted unit 9
Figure 2.5 Ceiling cassette 9
Figure 2.6 Floor console 9
Table 2.1 Heat pump components 10
Figure 2.7 Schematic diagram of reverse-cycle, air-to-air, split system heat pump operation (heating mode) 10
Figure 2.8 Schematic diagram of reverse-cycle, air-to-air, split system heat pump operation (cooling mode) 11
Figure 2.9 Schematic diagram of heat pump operation (heating) 11
Figure 2.10 Inverter operation 12
Figure 3.1 Schematic of heat pump performance 13
Figure 3.2 Graphic representation of heat pump efficiency 14
Table 3.1 Outdoor ambient temperature rating conditions 15
Table 4.1 Designing a heat pump system 16
Table 4.2 Effects of incorrectly sized systems 16
Figure 4.1 Floor-mounted unit – horizontal and vertical air discharge (heating) 18
Figure 4.2 Ceiling-mounted unit – horizontal air discharge (heating) 18
Figure 4.3 Ceiling-mounted unit – vertical air discharge (heating) 18
Figure 4.4 Wall/high wall-mounted unit – horizontal air discharge (cooling) 18
Table 4.3 External design temperatures by territorial authority (local council) areas 20
Table 4.4 Example of a heat pump performance guide chart 21
Figure 4.5 Outdoor unit clearances 21
Figure 4.6 Service access 22
Figure 4.7 Clearances required between outdoor unit and exchange LPG gas bottles 22
Figure 4.8 Locate the outdoor unit where a solid barrier can block the sound 23
Figure 4.9 Wall-mounted indoor unit clearances 23
Figure 4.10 Pre-install pipework before building claddings are installed 24
Figure 4.11 Permitted notching and drilling of timber framing allowed under NZS 3604 24
Figure 6.1 Twin-insulated and dehydrated pipe 26
Figure 6.2 Step 1: Cleaning the tube end 27
Figure 6.3 Step 2: Roughing the end surface 27
Figure 6.4 Step 3: Fitting insert when required to support pipe 27
5
Figure 6.5 Step 4: Adding ring 27
Figure 6.6 Step 5: Fitting connector marking stopline 28
Figure 6.7 Step 6: Applying sealant solution 28
Figure 6.8 Step 7: Fitting connector 28
Figure 6.9 Step 8: Compressing one connection end 28
Figure 6.10 Step 9: Completed compression connection 28
Figure 6.11 Pipe opening facing down when cutting 29
Figure 6.12 Cover pipe ends 29
Figure 6.13 Pipe bender 29
Figure 6.14 Cut pipe with tube cutters 30
Figure 6.15 Remove all burrs 30
Figure 6.16 Place the flare nut over the pipe end 30
Figure 6.17 Flare the end of the tube (A) 30
Figure 6.18 Flare the end of the tube (B) 30
Figure 6.19 Flare the end of the tube (C) 30
Figure 6.20 Flare the end of the tube (D) 31
Figure 6.21 Apply oil to the back of the flared pipe and the flare joint 31
Figure 6.22 Connect the pipes (A) 31
Figure 6.23 Connect the pipes (B) 31
Figure 6.24 Tighten connection (A) 31
Figure 6.25 Tighten connection (B) 31
Table 6.1 Fixing spacings for copper tubing 32
Figure 6.26 Run pipe/cable across truss chord/ceiling joist 33
Figure 6.27 Notch the top plate and studs (A) 33
Figure 6.28 Notch the top plate and studs (B) 33
Figure 6.29 Fix galvanised mild steel strap to hold pipe/cable 34
Figure 6.30 Wedge the pipe cable end into the stud 34
Figure 6.31 Braze pipe ends closed 34
Figure 6.32 Fix galvanised mild steel strap to hold pipe/connection cable 34
Figure 6.33 Feed pipe/cables through building wrap 34
Figure 6.34 Seal pipes or sleeve 34
Figure 7.1 Maximum pipe length and height 36
Figure 7.2 Screw-fix installation plate 36
Figure 7.3 Drill a hole through the wall 37
Figure 7.4 Slope of wall penetration 37
Figure 7.5 Release the tubing and drainage hose 37
Figure 7.6 Feed the connecting cable through the wall 37
Index of figures and tables
6
Figure 7.7 Tape tubing, drainage pipe and connecting cable together 37
Figure 7.8 Feed taped bundle through the hole 37
Figure 7.9 Attach unit to wall bracket (A) 38
Figure 7.10 Attach unit to wall bracket (B) 38
Figure 7.11 Ensure unit is securely seated 38
Figure 7.12 Taped pipes, drainage pipe and connection cable through hole 38
Figure 7.13 Expose flared pipe ends 38
Figure 7.14 Unobstructed gap under outdoor unit fixed on concrete pad cast in place 39
Figure 7.15 Concrete pad construction 39
Figure 7.16 Fixing unit to a timber deck 40
Figure 7.17 Pack with plastic shims to level 40
Figure 7.18 Wall-mounted unit on brackets – masonry wall 40
Figure 7.19 Bind insulation with vinyl tape 41
Figure 7.20 Tape drainage hose to drainage outlet 41
Figure 7.21 Install trunking neatly 42
Figure 7.22 Fit refrigerant piping, drainage pipe and connecting cable into trunking 42
Figure 7.23 Fill hole around piping with sealant 42
Figure 7.24 Seal around cover 42
Figure 7.25 Fit cover over opening 42
Figure 7.26 Apply oil to the back of the flare and the outdoor unit 43
Figure 7.27 Connect pipes and tighten flare nut 43
Figure 7.28 Tighten flare nut connections 43
Figure 7.29 Remove vacuum pump and gauges (A) 44
Figure 7.30 Remove vacuum pump and gauges (B) 45
Figure 7.31 Remove vacuum pump and gauges (C) 45
Figure 7.32 Progressively release the vacuum 45
Figure 7.33 Tighten valve caps 45
Figure 9.1 Connect power supply cable to terminal block 48
Figure 9.2 Install lockable isolating switch (A) 48
Figure 9.3 Install lockable isolating switch (B) 49
Figure 9.4 Install lockable isolating switch (C) 49
Figure 9.5 Replace service cover to outdoor unit 49
Figure 9.6 Example of a nameplate on an outdoor unit 49
Index of figures and tables
7
1.0 IntroductionHeat pumps have become increasingly popular in New Zealand homes over recent years, as they are an energy efficient and convenient way of heating and cooling.
By using a relatively small amount of electricity, a heat pump can extract heat energy from one location – typically outdoor air – and transfer it to another location to provide heating. The reverse process can provide cooling.
Good design and installation are fundamental to a heat pump system’s effectiveness and efficiency. It involves understanding the importance of correct sizing for the ambient conditions, selecting the right unit for the local environment and correctly installing the unit.
This guide provides good practice guidelines for designing and installing the most common type of residential heat pump system – air-to-air single-split heat pump systems (also known as reverse-cycle air conditioners), used primarily for heating.
The guide is aimed at experienced installers of heat pumps, and it gives the process to follow for system design and installation into both new and existing homes.
Note that this guide does not cover:• multi-split or ducted heat pump systems• ground-to-air, water-to-air or water heating systems• DIY installations – EECA recommends heat pump systems are installed by
experienced installers• weathertightness and airtightness of the building envelope and structural integrity
(though this must be maintained).
Before you begin
Insulate firstBefore installing a heat pump into any home, reduce heat loss as much as possible by:• adding ceiling and underfloor insulation where practicable• adding weather stripping to doors and windows• eliminating draughts.
Ensure you are qualified and preparedThe installation of any heat pump system should be carried out by suitably qualified installers who:• have the correct toolkit to allow them to carry out the work• are licensed to carry out the electrical work• hold an Approved Filler Compliance Certificate for the handling of refrigerants.
• NOTE: New regulations are underway that will require heat pump installers to have suitable qualification/ certification/ registration from 1 January 2020. Check with your industry association for updates (www.irhace.org.nz).
Know your standards and regulationsStandards and regulations applicable to a heat pump installation that must be complied with include the following:• Building Code Clauses B1 Structure, E2 External moisture and G9 Electricity• Electricity (Safety) Regulations, including the cited edition of AS/NZS 3000 Electrical
installations (known as the Australian/New Zealand Wiring Rules)• New Zealand electrical codes of practice• Health and Safety at Work Act (HSWA) 2015• Australia and New Zealand Refrigerant Handling Code of Practice 2007 and standards• Consumer Guarantees Act 1993, which places a legal obligation on the installer to
install a system that is suitable for the situation it is installed in• Energy Performance – AS/NZS 3823 units must meet minimum energy performance
requirements and have suitable labelling provided.
air in
indoor unit
heat outoutdoor
unit
Figure 2.1 Split system heat pump
outdoor unit
heat out heat out
indoor units
air in
Figure 2.2 Multi-split system heat pump
outdoor unit
Figure 2.3 Ducted heat pump system
heat out heat out
compressor
air in
duct duct
8
Multi-split system – consisting of an outdoor unit supplying a number of indoor units (Figure 2.2). Not covered by this guide.
Ducted system – consisting of an outdoor unit and a compressor (located outside or in the roof space) that is connected to a number of air supply outlets in selected rooms or zones in the house. Zones can be controlled individually or by a centrally located controller (Figure 2.3). Not covered by this guide.
This section provides a general overview of heat pump types, components and how heat pumps work.
2.1 Types of heat pump systems
Air-to-air, reverse-cycle heat pump configurations are shown below.
The most commonly installed residential heat pump in New Zealand is an air-to-air, single-split system. This guide covers design and installation of this type of system only.
Single-split system – consisting of an outdoor unit and a single indoor unit connected to the coil by pipework containing the refrigerant (Figure 2.1).
2.0 Heat pump systems
9
Indoor units may be:
• high wall-mounted (Figure 2.4) Figure 2.4 High wall-mounted unit
• ceiling-mounted cassette (Figure 2.5) Figure 2.5 Ceiling cassette
• floor console (Figure 2.6) Figure 2.6 Floor console
More information on positioning of heat pumps can be found in Section 4.0 Designing a heat pump system.
10
2.2 Components of a heat pump
The main components of an air-to-air heat pump and how they operate are described in Table 2.1 and shown in Figures 2.7, 2.8 and 2.9.
Table 2.1 Heat pump components
Component Description
Evaporator A heat exchanger that absorbs heat from the surroundings.• For heating, it is the outdoor unit.• For cooling, it is the indoor unit.
Condenser A heat exchanger that releases heat to the surroundings.• For heating, it is the indoor unit.• For cooling, it is the outdoor unit.
Compressor Reduces the refrigerant gas volume by compressing it, causing the gas temperature and pressure to rise, and pumps the refrigerant around the pipework/system. The compressor operates as a variable-speed system (see 2.4 Variable Speed (inverter) compressors).
Metering device Allows the refrigerant condensate (liquid) to expand, lowering the pressure and temperature.
Coil/pipework Continuous, closed-circuit tubing through which refrigerant flows and heat transfer occurs. The pipes generally have fins to increase the surface area for the heat exchange process (see 6.0 Installing pipework).
Refrigerant The compound that circulates through the heat pump system in both liquid and gas state, alternately absorbing and releasing heat (see 8.0 Refrigerants).
Reversing valve Changes the direction of flow of the refrigerant to reverse the heat pump function from heating to cooling or vice versa. Reversing the heat pump function also occurs when the heat pump switches into defrost mode (see 3.4 Impacts of defrost cycle on efficiency and heat output).
Fan Draws air across the evaporator coil (for heat extraction) and moves air away from the condenser coil (for heat distribution/removal).
ambient air in
outdoor
gas flow
evaporator
cool air out
heated supply air out
reversing valve
compressor
condenser
return air in
liquid flow
metering device
indoor
Figure 2.7 Schematic diagram of reverse-cycle, air-to-air, split system heat pump operation (heating mode)
11
Figure 2.8 Schematic diagram of reverse-cycle, air-to-air, split system heat pump operation (cooling mode)
return air inoutdoor
gas flow
cool supply air out
reversing valvecompressor
condenser
heated air outliquid flow
metering device
indoor
evaporator
ambient air in
Figure 2.9 Schematic diagram of heat pump operation (heating)
heat in heat ingas: low temperature low pressure
Evaporator
Compressor
Condenser
Metering Device
gas: low temperature low pressure
gas: high temperature high pressureliquid:
low temperature high pressure
liquid: low temperature high pressure
heat outheat out
12
Tem
pera
ture
(°C
)
Time
set temperaturetemperature range
fluctuation
Figure 2.10 Inverter operation
2.3 How a heat pump works
In broad terms, air-to-air heat pumps work by using electrical energy to extract energy from the outside air and transfer it inside as heat, which makes it an efficient way of heating. Reversing the process enables indoor heat to be removed to provide cooling.
A more detailed illustration of how a heat pump operates in heating mode can be seen in Figure 2.9. There are five main processes in the cycle:
1. In the evaporator (outdoor unit), low-pressure, low-temperature liquid refrigerant absorbs heat from its surroundings and evaporates, converting to a gas state and absorbing energy as it does so (latent heat of evaporation).
2. It passes through the compressor, where the low temperature gas is reduced in volume, resulting in a rise in both temperature and pressure.
3. As a heated and high-pressure gas, it passes through the condenser (indoor unit), where the gas condenses (latent heat of condensation) with a release of heat into the air surrounding the coil. A fan moves the warmed air away from the coil to distribute it throughout the indoor space.
4. Still under pressure, the cooled refrigerant, now in liquid state, passes through the metering device, where rapid expansion results in a reduction in pressure.
5. In the low-pressure, low-temperature state, the refrigerant flows back into the evaporator, and the cycle is repeated.
2.4 Variable-speed (inverter) compressors
The compressor of a modern heat pump is commonly a variable-speed compressor – also known as an inverter compressor. Heat pumps with variable speed (inverter) compressors are more efficient than heat pumps with fixed speed compressors.
An inverter or variable-speed compressor has a number of advantages over fixed-speed units which are no longer common.
They have a 'soft start' and run at variable speed, decreasing as the temperature approaches set point and increasing as the temperature begins to fall. The varying speed delivers heating or cooling as required and maintains a more constant temperature that has smaller fluctuations (Figure 2.10). This results in improved efficiency, reduced vibration and quieter operation.
3 kW out
2 kW from air
1 kW electricity
Figure 3.1 Schematic of heat pump performance
13
3.0 Heat pump performanceThis section covers the different factors that influence the efficiency and performance of heat pumps.
Understanding heat pump performance is essential when it comes to selecting a heat pump (which is covered in Section 4.0 of this guide).
In theory, the total heat that could be available for heating is the sum of the heat extracted from the source plus the energy required to drive the heat pump. Thus, if 1 kWh of electricity is required to drive a heat pump and 2 kWh of energy can be extracted from the heat source, the total energy delivered could theoretically be 3 kWh, giving an efficiency of 300% (Figure 3.1).
In practice, other factors influence the actual efficiency of a heat pump:• climate• heating and cooling demands• source and supply temperatures• auxiliary energy consumption (pumps, fans)• heat pump size to meet heating/cooling demand• operating characteristics.
3.1 Heat pump efficiency
Heat pump efficiency is the ratio of the heating or cooling delivered, compared to the electrical energy required to operate the system.
The ratios are given in two ways:• coefficient of performance (COP) – the ratio of heating delivered, compared to the
electrical energy input• energy efficiency ratio (EER) – the ratio of cooling delivered, compared to the
electrical energy input.
The higher the COP or EER, the greater is the efficiency of the heating or cooling system.
You can calculate the COP by taking the heating output (in kW) and dividing it by the electrical input (in kW).
These values can be found on the energy rating label (see Section 3.2) or manufacturer’s information.
An acceptable level of COP should be at least 3, and better products may well have a COP of 4 or more.
NOTE: Heat pump efficiency ratios are sometimes presented as ACOP and AEER, which are annualised figures that includes standby power in the calculation.
14
3.2 Energy rating label
The energy rating label gives information on how much energy a product uses so you can compare models. Every heat pump sold in New Zealand must display this label. The number of stars tells you how well the product performs – the more stars the better.
3.3 Effects of temperature on efficiency and heating capacity
Efficiency and heating capacity of a heat pump system are not constant – they vary along with the temperature differential between indoor and outdoor air. A heat pump’s rated efficiency and heating capacity are for particular outdoor temperatures and heating/cooling loads. When designing a system it is important to understand how it will perform at lower temperatures.
As the difference between outdoor temperature and desired indoor temperature increases, the efficiency of a heat pump system decreases. This is illustrated in Figure 3.2, which shows the efficiency of a heat pump in heating mode reducing as the outdoor temperature decreases.
Different heat pumps will perform very differently at sub-zero temperatures – some may keep performing down to -20˚C while others will struggle at temperatures below freezing.
Figure 3.2 Graphic representation of heat pump efficiency
Outside Air Temp (ºC)
Another temperature-related factor that affects heating efficiency is the extra energy required for defrosting at low temperatures. At temperatures up to around +7 degrees Celsius, any water vapour in the air may start to condense and freeze onto the evaporator (outdoor heat exchanger) coils. This will disrupt the heat flow, and the coils must be de-iced for heating to be able to continue (see Section 3.4 Impacts of defrost cycle on efficiency).
15
Heat pumps are rated for efficiency and capacity output under laboratory conditions at a particular ambient outdoor temperature. However, actual mid-winter temperatures in some parts of New Zealand, particularly in the central North Island and in the South Island, will give significantly different performance.
For this reason, standardised testing of heat pumps can be done at three levels of specific temperature and humidity. These are called H1, H2 and H3 and are shown in Table 3.1.
Table 3.1 Outdoor ambient temperature rating conditions
Rating Outdoor ambient temperature (˚C) rating conditions
Dry bulb (DB)
H1 7˚C
H2 2˚C
H3 -7˚C
These ratings allow you to use a range of design temperatures to select heat pumps for areas where the temperature may often be below 0˚C. This is important to ensure that the heat pump will be able to provide the required heating capacity at low outdoor temperatures relevant for the local climate of the home or building (see 4.5 Step 3: Calculate heat load requirement).
Manufacturers will also often test their product at other temperatures (e.g. -5, 0, 5, 10˚C etc).
3.4 Impacts of defrost cycle on efficiency and heat output
For optimal heat pump efficiency and performance, you must size a system correctly to minimise the energy losses and disruptions to heating delivery that occur during the defrost cycle.
The defrost cycle is necessary to remove ice build-up on evaporator coils. Ice build-up occurs from below 7˚C (especially in high humidity), when any water vapour in the air will start to condense and freeze onto the evaporator (outdoor heat exchanger) coils.
This will disrupt the heat flow, and the coils must be de-iced for heating to be able to continue.
To remove ice build-up on the coils, most heat pumps have a defrost cycle where the system switches into cooling mode (taking some heat from inside the home), which effectively cools the room slightly.
Some systems have a closed-loop cycle to use waste heat from the motor/compressor to defrost the coils.
During defrosting, no heat is supplied to indoors.
Undersized heat pumps will need to defrost frequently in low ambient temperatures, reducing the system’s efficiency and ability to provide sufficient heating.
The defrost cycle control is either:• a time-temperature defrost, starting and stopping at preset times (30-, 60- or
90-minute intervals); or• on-demand defrost, which is generally more efficient because it operates only when
it detects frost build-up on the outdoor coil by monitoring air and coil temperature, outdoor airflow, pressure differential across the coil and refrigerant pressure.
Note: If a heat pump goes into multiple defrosts over a short time frame (1-2 hours), the unit should be serviced. This issue could also occur where the heat pump is undersized and struggling to heat the space.
Systems that include a dry-coil defrost cycle briefly run the outdoor fan at maximum speed before the system starts to heat again, to remove any water that may still be on the coil fins and would immediately refreeze. This operation can be seen by water vapour blowing from the outdoor unit before the heating cycle resumes.
16
4.0 Designing a heat pump systemThis section describes the steps for designing a heat pump system that will perform as efficiently as possible to meet the customer’s needs.
4.1 Steps for designing a heat pump system
For a well-designed heat pump follow the four steps shown in Table 4.1. Each step is described in detail in Sections 4.3 to 4.7.
Table 4.1 Designing a heat pump system
Step Action
1 Determine requirements (Section 4.3): • for heating/cooling • for the building• for the environment (e.g. protection for system
components in coastal/geothermal regions)• for the type of unit suited to the room.
2 Determine heating capacity (kW) requirement and external design temperature (Sections 4.4 and 4.5).
3 Select the system/model to suit the design requirements and occupant preferences (Section 4.6).
4 Select the locations of the indoor and outdoor units (Section 4.7).
4.2 The importance of correct heat pump sizing
Correct heat pump sizing is critical to efficiency and performance. Select a unit that can provide the required heating capacity at the external design temperature relevant for the location of the home or building.
If the heat pump capacity is too low, the system will use more energy than necessary (increasing running costs), will likely need to defrost more frequently during heating operation, and may not be able to provide sufficient heating/cooling to achieve the indoor temperatures required for occupant comfort (Table 4.2).
The extra running costs of an undersized heat pump generally outweigh the additional cost of installing a unit that is the next size up.
Selecting a slightly oversized heat pump provides a safety margin to ensure that heating/cooling requirements will be met. It may also result in improved energy efficiency.
However, significant oversizing should be avoided.
Table 4.2 Effects of incorrectly sized systems
If unit is: Performance Effects
Undersized Operation may be in defrost mode too often (see 3.4 Impacts of defrost cycle on efficiency and heat output).
• System is not delivering heat.• System may be blowing out cold air.
Operation may be at full capacity too often.
• Increased running costs.• Reduced efficiency.• Undue wear and tear, premature failure
of equipment
Oversized significantly
Increased start-up power use. • Increased running costs.• Reduced efficiency.
Short cycling because output exceeds demand.
• Too much air movement (draught) even at low fan speed.
• Increased noise.• Undue wear and tear.
Runs at low load too often. • Reduced efficiency.
17
Where the space being heated is large, installing two smaller units or a multi-split system may give better heat distribution within the space and better control than a large-capacity single unit.
4.3 Step 1: Determine requirements
As a first step, gather the information that you will need to determine what the most appropriate heat pump option is for a particular home. Use the checklists below to determine requirements for the system.
4.3.1 Checklist of heating/cooling requirements
❏❏ What is required? For example, is it mainly heating or cooling?
❏❏ What is the region and location of the building?
❏❏ Are there specific local conditions, such as microclimates within the climatic zones, which may influence selection?
❏❏ What are the seasonal high and low ambient temperatures?
❏❏ What type of home is the system for? For example, old, new, insulated.
❏❏ Is it for a typical single room or a large or open plan room/hallway (where more than one unit may be required)?
❏❏ What is the owner preference for the type of indoor unit? For example, a floor-mounted unit may be better for an older user to give more direct heat flow and allow easier access for maintenance. A high wall-mounted or ceiling-mounted unit can provide more effective cooling and allows occupants more flexibility with arranging furniture in the room.
❏❏ Does the owner prefer a unit that can be controlled remotely (e.g. a Wi-Fi enabled unit)?
4.3.2 Checklist of building conditions
❏❏ Building orientation.
❏❏ Window orientation and solar gain, particularly in summer.
❏❏ Areas of walls, ceilings, windows and floors.
❏❏ Building envelope; for example, air infiltration/heat loss around doors/windows.
❏❏ Insulation levels of walls, ceilings and floors.
❏❏ Single/double glazing.
4.3.3 Environmental requirements
Select a unit that is suitable for the environment it is being installed in.
For example, geothermal regions require the indoor and/or outdoor units, coil and pipework to be protected against atmospheric sulphur-containing gases that will cause corrosion of the coil.
Coastal regions also require protection against corrosion for both the outdoor cabinet and the coils. Use a proprietary coil protectant available to installers in those areas.
18
Figure 4.3 Ceiling-mounted unit – vertical air discharge (heating)
Figure 4.1 Floor-mounted unit – horizontal and vertical air discharge (heating)
4.3.4 Type of unit suited to room
Consider the options for airflow patterns in relation to room or space layout (Figures 4.1 – 4.4). All three types of unit can be used for heating or cooling. Different types may suit different people based on their own personal choice.
Floor console units are primarily designed for heating, as warm air rises and cold air falls (Figure 4.1). Consider the location of objects such as furniture that may interfere with airflow and cause short circuiting of the air back to the unit, reducing efficiency and performance.
Figure 4.2 Ceiling-mounted unit – horizontal air discharge (heating)
Figure 4.4 Wall/high wall-mounted unit – horizontal air discharge (cooling)
Ceiling-mounted units blow air down or out from the unit to circulate the warmed air within the room (Figures 4.2 and 4.3).
High wall-mounted units blow hot or cool air to mix with room air before dropping to the level of occupants (Figure 4.4).
4.4 Step 2: Calculate heat load requirement
Using the information from Step 1, you can now calculate the required heating capacity for the heat pump.
For rental homes, the Residential Tenancies (Healthy Homes Standards) Regulations 2019 include minimum requirements for heaters in the main living room. From 1 July 2019, a heat pump newly installed in the main living room of a rental home should at least have the heating capacity required by these regulations.
To determine the minimum heating capacity required by the Residential Tenancies (Healthy Homes Standards) Regulations 2019 you can either:
• use the heating assessment tool available on the Tenancy Services website, or• do a manual calculation in accordance with Schedule 2 of the Residential Tenancies
(Healthy Homes Standards) Regulations 2019.
Use these heater sizing methods for heat pumps installed in the living room of any home, not just rental homes. This will ensure the heat pump can meet the requirements if the home was to become a rental home.
These heater sizing methods are also suitable for rooms other than the main living room, for example a secondary living room or a bedroom.
4.4.1 Heating assessment tool on Tenancy Services website
Tenancy Services is part of the Ministry of Business, Information and Employment (MBIE). Its website provides information to residential landlords and tenants and includes an online heating assessment tool.
The online heating assessment tool aims to help landlords determine what type and capacity heater rental homes require in the main living room to comply with the Residential Tenancies (Healthy Homes Standards) Regulations 2019.
Whilst these regulations only apply to rental homes, the heating assessment tool is suitable for determining the required heating capacity for any room in both rental and owner-occupied homes in New Zealand.
The Tenancy Services heating assessment tool is available on: www.tenancy.govt.nz/heating-tool
4.4.2 Manual calculation of required heating capacity
You can also calculate the required heating capacity manually. For details, refer to Schedule 2 of the Residential Tenancies (Healthy Homes Standards) Regulations 2019.
This calculation method is suitable for determining the required heating capacity for any room in both rental and owner-occupied homes in New Zealand.
The Residential Tenancies (Healthy Homes Standards) Regulations 2019 are available on: www.legislation.govt.nz/regulation/public/2019/0088/latest/whole.html
19
20
4.5 Step 3: Determine external design temperature
Because the heating capacity of a heat pump reduces with outdoor temperature, a unit must be selected that can provide the required heating capacity at the lowest winter outdoor temperature relevant to the local climate where the heat pump is being installed. The heat pump’s capacity at that temperature will likely be different to the rated heating output capacity.
Table 4.3 lists external design temperatures for all territorial authority (local council) areas of New Zealand, as provided in Schedule 2 of the Residential Tenancies (Healthy Homes Standards) Regulations 2019.
Note that there may be some variation within each area. If the location where the heat pump is being installed has a particularly severe climate or microclimate (for example, a sunless or damp valley), this needs to be taken into consideration. In this case, the design temperature may be one or two degrees lower.
Table 4.3 External design temperatures by territorial authority (local council) areas
Territorial authority Outdoor (°C)
Ashburton District Council -5
Auckland Council 1
Buller District Council -3
Carterton District Council -4
Central Hawke's Bay District
Council
-3
Central Otago District Council -8
Chatham Islands Council -1
Christchurch City Council -4
Clutha District Council -4
Dunedin City Council -4
Far North District Council 2
Gisborne District Council 0
Gore District Council -4
Grey District Council -2
Hamilton City Council -3
Hastings District Council -2
Hauraki District Council -2
Horowhenua District Council -3
Hurunui District Council -5
Hutt City Council -1
Invercargill City Council -4
Kaikoura District Council 1
Kaipara District Council 1
Kapiti Coast District Council -3
Kawerau District Council -2
Mackenzie District Council -10
Manawatu District Council -2
Marlborough District Council -3
Masterton District Council -4
Matamata-Piako District Council -3
Napier City Council -2
Nelson City Council -3
New Plymouth District Council 0
Opotiki District Council -2
Territorial authority Outdoor (°C)
Otorohanga District Council -3
Palmerston North City Council -3
Porirua City Council 0
Queenstown Lakes District Council -6
Rangitikei District Council -4
Rotorua Lakes Council -3
Ruapehu District Council -5
Selwyn District Council -4
South Taranaki District Council -1
South Waikato District Council -3
South Wairarapa District Council -4
Southland District Council -6
Stratford District Council -2
Tararua District Council -3
Tasman District Council -4
Taupo District Council -5
Tauranga City Council 0
Thames-Coromandel District
Council
-1
Timaru District Council -5
Upper Hutt City Council -3
Waikato District Council -2
Waimakariri District Council -4
Waimate District Council -5
Waipa District Council -3
Wairoa District Council 0
Waitaki District Council -5
Waitomo District Council -3
Wellington City Council 2
Western Bay of Plenty District
Council
-1
Westland District Council -2
Whakatane District Council -2
Whanganui District Council -1
Whangarei District Council 2
21
500 mm
150 mm
600 mm service access
600 mm
150 mm
Figure 4.5 Outdoor unit clearances
4.6 Step 4: Select a system to meet requirements
You should now have all the information needed to select the right heat pump system for the home’s needs. Things to keep in mind:
• Inverter type units are recommended in most cases for their increased efficiency.
• Consider suitability for the environment (i.e. sea spray, sulphur from geothermal activity).
Some manufacturers provide performance guide charts for selecting a heat pump system similar to Table 4.4. You should use products with this information available, particularly in colder climates.
Where heating capacity data is not available for the precise external design temperature relevant to the installation site, use the heating capacity information for the nearest outdoor temperature available below the external design temperature.
Table 4.4: Example of a heat pump performance guide chart
Model A: Capacity 4.0 kW rated outputIndoor (°C) Outdoor (°C)
20 -10 -5 0 2 7
Output Input COP Output Input COP Output Input COP Output Input COP Output Input COP
2.4 0.77 3.12 2.88 0.91 3.15 3.7 1.1 3.31 3.8 1.12 3.4 4.1 1.18 3.5
Model B: Capacity 6.0 kW rated outputIndoor (°C) Outdoor (°C)
20 -10 -5 0 2 7
Output Input COP Output Input COP Output Input COP Output Input COP Output Input COP
3.6 1.3 2.76 4.32 1.54 2.8 5.1 1.71 2.98 5.2 1.75 3.0 6.1 1.9 3.2
Model C: Capacity 8.0 kW rated outputIndoor (°C) Outdoor (°C)
20 -10 -5 0 2 7
Output Input COP Output Input COP Output Input COP Output Input COP Output Input COP
4.8 1.85 2.59 5.65 2.05 2.75 6.2 2.25 2.8 6.4 2.4 2.7 8.1 2.6 3.1
As an example, for a required heating capacity of 5.6 kW and an external design temperature of +1°C, by referring to the example performance guide chart in Table 4.4, an 8 kW rated capacity heat pump should be selected as it is able to deliver 6.2 kW output at 0°C (nearest temperature below +1°C with data available), which will meet the heating capacity requirement. The 6 kW rated capacity heat pump model only provides 5.1 kW output at 0°C which is less than the required 5.6 kW and therefore insufficient.
4.7 Step 5: Locate the units
Correct location of both outdoor and indoor units is essential for optimum performance. Many problems with poorly performing heat pumps are due to poor location of units.
4.7.1 Outdoor units
Locate outdoor units:• to allow unimpeded air flow around the unit
(to avoid the creation of a microclimate that reduces heat pump performance and efficiency)
• in a position that gets full sun in winter• in accordance with the manufacturer’s
recommendations for distances to obstructions. If the manufacturer’s recommendations are not given, provide the following minimum distances from obstructions:
– 500 mm between air inlet and outlet faces
– 600 mm above the unit
– 150 mm to other faces (Figure 4.5).
22
Figure 4.6 Service access
Figure 4.7 Clearances required between outdoor unit and exchange LPG gas bottles
500 mm
1500 mm
500
mm
Within space 0.5 m above and 0.5 m laterally from any cylinder valve, extending 1.5 m laterally at the base of the cylinder.
= Zone 2
Locate the units:• to minimise refrigerant pipe run lengths and
bends• to give minimum pipe runs in accordance with
the unit manufacturer’s instructions• where condensate can easily be drained away• to allow access for service (minimum 600 mm)
(Figure 4.6)• where any blockage (such as from leaves or
snow) is quickly seen and can be cleared away.
Locate the units:• to be protected from the sea spray in coastal
areas, sheltered from frost and strong wind (strong wind can cause the condenser fan to spin in reverse and burn out the motor, which is a particular problem when a unit is located on a roof)
• where condensation can be appropriately drained away (see 6.1.8 Positioning and connecting the condensate drainage pipe) condensation will always be produced during heating and must be able to be drained safely
• in a well ventilated area, and at a safe distance from any gas sources or appliances:– 1.5 m clearance from an exchange LPG bottle (i.e.
gas cylinders that get swapped and refilled offsite).– 3.5m clearance from an in-situ fill LPG bottle
(i.e. gas cylinders that get refilled by tanker onsite)– 0.5 m clearance from a gas water heater.
NOTE:• DO NOT locate where noise can cause a disturbance to home occupants or to
neighbours (see Section 4.7.1.1 for more information)• DO NOT locate under the house or a deck, or any location that may impede airflow,
only install where there is ample space and clearance• DO NOT locate below a window where the unit has a vertical discharge• DO NOT locate so that multiple units are competing against each other for air flow• DO NOT locate where the air outlet is directed to where people pass, such as
across an accessway or path• DO NOT locate the outdoor unit on a balcony or deck that is more than 1 m above
a surface below in a way that facilitates climbing over the balustrades or railings. Any screen around the outdoor unit must not facilitate climbing and must not include toe holes.
direction of sound
outdoor unit
solid fence/barrier to block sound
Figure 4.8 Locate the outdoor unit where a solid barrier can block the sound
150 mm
150 mm
2.0 m (high wall) to underside
40-150 mm
Figure 4.9 Wall-mounted indoor unit clearances
23
4.7.1.1 Avoid noise disturbance
Locate outdoor units where noise from the unit cannot transmit to and disturb the home occupant or adjacent properties. Do not install the outdoor unit under or close to bedroom windows. Comply with council bylaws regarding permitted noise levels at the property boundary.
There are several ways to reduce sound transmission:• Locate the unit where a fence or solid barrier can block sound so that the line of sight
between source and receiver is blocked (Figure 4.8). • At the same time avoid reflected sound
transmission – consider the reverberation effects of lightweight materials such as corrugated iron fencing.
• Mount the unit on isolation mounting blocks or pads to absorb vibration.
• Ensure the owner is aware of the need to carry out regular maintenance to have worn bearings or other noisy parts replaced.
• Refer to the manufacturer’s mounting instructions for recommended clearances to ensure airflow around the unit.
4.7.2 Indoor units
Locate indoor units:• according to the type of unit, i.e. high wall, under-ceiling, floor-mounted• on an external wall if possible• to avoid directing airflow onto seating locations or electronic equipment • to direct airflow to the coldest point in the room (but not towards a window)• appropriately for room layout and airflow patterns• in accordance with the manufacturer’s recommendations for minimum clearances.
Otherwise allow:
– 40-150 mm minimum above and 150 mm minimum on either side of a wall-mounted unit
– 2.0 m minimum (measured to the bottom of the unit) above floor for a high wall or ceiling-mounted unit
– 50 mm minimum to each side for a floor console (Figure 4.9)
• so that a clear airflow path is maintained• to minimise refrigerant pipe run lengths and
bends (for each 90° bend, deduct 1% from the heat pump heating/cooling capacity)
• so that the condensate drainage pipe can drain to outside without the need for a condensate pump.
NOTE:• DO NOT locate in a tight corner or space• DO NOT locate behind a grille• DO NOT locate so it directs air to a primary source of heat gain or loss,
such as windows• DO NOT locate where there may be any steam• DO NOT locate within a kitchen or near an automatic insect repellent dispenser• DO NOT locate above or close to any heat source, including electrical appliances,
which could affect the performance or act as an ignition point.
24
Wall plates
Studs
70 x 45 mm top or bottom plate
19 mm max. diameter
75 x 45 mm stud 90 x 45 mm stud
19 mm max. depth 25 mm max. diameter
19 mm max. depth for max. 200 mm length or 22 mm cut for diagonal timber bracing 25 mm max. depth for max. 200 mm
length or 35 mm for a max. of three consecutive studs
90 x 45 mm top or bottom plate
25 mm max. depth200 mm max. length
25 mm max. diameter
4.7.3 Building work
4.7.3.1 New building
The best time to install pipework and cables in a new building is when it is still under construction. Co-ordinate with the other trades and plan the layout and location of the system early in the building design stage so that penetrations through the building envelope can be made before the cladding is installed (Figure 4.10)
– Note that the penetration through the wall underlay has not incorporated a sleeve and has not yet been taped off with flexible flashing tape.
– Protect pipework and cables from being damaged by other trades. Sleeving or plastic inserts can be used to prevent pipes from being kinked.
Building Code acceptable solution E2/AS1 gives guidance on making penetrations through the wall cladding and wall underlay – a copy is available for download from the building.govt.nz website.
If you make the penetration through the wall cladding system, then you are responsible for the weathertight performance of the penetration made. You will be liable for any non-performance due to your work.
Any drilling, notching or cutting of load-bearing and support walls to fit pipes must be within the limits specified by NZS 3604:2011 Timber framed buildings. Figure 4.11 outlines the maximum permitted allowances for drilling and notching a top plate may be required.
4.7.3.2 Existing building
When installing units into an existing building:• Identify the location of existing pipework, studs and cables before drilling holes
or making penetrations in the building.• Ensure any drilling, notching or cutting of load-bearing and support walls to fit
pipes is within the limits specified by NZS 3604:2011 Timber framed buildings (shown in Figure 4.11).
Figure 4.10 Pre-install pipework before building claddings are installed
NOTE: Notches in studs to be spaced at a min. of 600 mm apart.
Figure 4.11 Permitted notching and drilling of timber framing allowed under NZS 3604
19 mm max. depth200 mm max. length
25
5.0 ToolkitUse the correct tools and equipment as per the following list.
Equipment❏❏ Brazing equipment
❏❏ Set of standard hand tools
❏❏ Pipe benders
❏❏ De-burring tool
❏❏ Swaging set
❏❏ Flaring tools
❏❏ Wrenches
❏❏ Torque wrenches
❏❏ Pipe cutters
❏❏ Electronic scales
❏❏ Digital thermometer
❏❏ Oxygen free nitrogen gas cylinder with pressure gauge and manifold valve and flexible clear hose
❏❏ Leak testing equipment
❏❏ Electronic leak tester
❏❏ Vacuum pump with backflow prevention device
❏❏ Manifold set
❏❏ Hose adaptors
❏❏ Auto ignition gas torch
❏❏ Digital vacuum gauge
❏❏ Refrigerant specific valve core removal tool
❏❏ Tape measure
❏❏ Charge valve
❏❏ Compression or locked-ring jointing tool
❏❏ Recovery cylinder
❏❏ Charge hose and connector
❏❏ Stud finder
❏❏ Safety glasses, gloves, ear protection, safety boots, hard hats and other PPE
Materials❏❏ Copper pipe (hard/soft drawn, twin-insulated, dehydrated)
❏❏ Pipe protection
❏❏ Pipe insulation
❏❏ Electrical cable
❏❏ Oil for flared joints (refrigerant compatible)
❏❏ Galvanised mild steel straps 120 x 25 x 0.5mm
❏❏ Galvanised pipe brackets 65mm diameter
❏❏ Galvanised nails 30mm
❏❏ Condensate drainage pipe, either smooth, hard PVC pipe (best practice option) or flexible, ribbed pipe
❏❏ Vinyl tape
❏❏ Electrical conduit
❏❏ Gas cylinder with refrigerant that is compatible with heat pump
26
6.0 Installing pipeworkGood pipework gives a safe, efficient and reliable installation necessary for the heat pump system to perform properly. Too many joints, bends and long lengths can increase the risk of leaks and reduce efficiency, as it requires more energy for the compressor to pump the refrigerant around the system.
Many system failures occur due to poor workmanship of pipework installation. To reduce the likelihood of problems:• pipes must be clean and moisture-free• use pipe sizes recommended by the manufacturer• design pipelines for the shortest runs and minimum number of bends to limit internal
friction:
– floor consoles may not have a minimum pipe run and can be installed back to back
– high wall units have a minimum pipe run, typically 3.0-5.0m – check the manufacturer’s instructions for this information
• insulate and protect all pipework with a rated UV capping• slope pipes towards the compressor to allow any oil that gets into the pipes to drain
back to the compressor sump (some compressor oil will likely get into the pipeline in any system, and if it remains there it will de-rate the system’s pressure and hence its efficiency)
• install pipelines to allow for seismic, wind and thermal movement• pipes must be rated for the refrigerant pressure being used in the system.
6.1 Pipework installation
Good-quality pipework involves the following steps:
1. Selecting suitable pipework and jointing (see Sections 6.1.1 and 6.1.2).
2. Ensuring pipework is clean (see Section 6.1.3).
3. Making bends properly (see Section 6.1.4).
4. Creating flared joints properly (see Section 6.1.5).
5. Ensuring pipework is well-supported (see Section 6.1.6).
6. Insulating refrigerant pipework (see Section 6.1.7).
7. Positioning and connecting the condensate drainage pipe properly (see Section 6.1.8).
6.1.1 Types of pipework
Copper pipework forms the closed-coil system through which refrigerant flows. Copper may be hard-drawn or soft-drawn.
Hard-drawn is recommended as best practice for pipe diameters of 20 mm and more, but soft-drawn is commonly used because it is easier to work with.
Use UV-rated twin-insulated and dehydrated pipe, which is easier to install in trunking and in ceiling spaces (Figure 6.1).
Figure 6.1 Twin-insulated and dehydrated pipe
27
Figure 6.2 Step 1: Cleaning the tube end
Figure 6.4 Step 3: Fitting insert when required to support pipe
Figure 6.3 Step 2: Roughing the end surface
Figure 6.5 Step 4: Adding ring
6.1.2 Types of jointing
You can joint pipes by brazing or compression (lock-ring) jointing.
6.1.2.1 Brazed connections
Brazed joints provide the best resistance to pressure, temperature and stress vibrations, and using this type of jointing is recommended as good practice. Pipe joints behind the indoor unit and in wall spaces must be brazed, as brazed pipe connections reduce the likelihood of leaks and take up less space. Carry out all brazing with oxygen-free nitrogen (OFN) circulating through the pipework – this will avoid a build-up of carbon in the pipe, which will cause oil sludging, filter blockage and eventual system failure.
6.1.2.2 Compression connections
Compression connections are an alternative to brazed connections and are far more reliable than flare joint connections. Compression connections, as shown below, have become more popular in recent years for a variety of reasons:
1. 100% leak free, unlike flare connections (provided the correct assembly procedure is followed).
2. Clean, efficient and reliable.
3. No need for heavy brazing gear and associated flame, especially where there is a special fire hazard.
4. Able to be installed indoors while building occupants are around.
5. Suitable for HC, HFC, HFO and CO2 refrigerants.
6. UL, TUV, and EN/ISO approved.
7. Max. 75 bar operating pressure, so suitable for high pressure refrigerants.
8. No requirement for nitrogen for brazing or purging.
9. Ability to connect differing pipe materials together.
10. Available from 6mm (1/4”) to 42mm (1 5/8”).
Figures 6.2 - 6.10 show an example of assembling a compression connection.
28
Figure 6.6 Step 5: Fitting connector marking stopline
Figure 6.8 Step 7: Fitting connector
Figure 6.10 Step 9: Completed compression connection
Figure 6.7 Step 6: Applying sealant solution
Figure 6.9 Step 8: Compressing one connection end
6.1.2.3 Flared joints
Flared joints have a higher risk of the refrigerant leaking but may be required where connecting the pipe to the outdoor unit.
If poorly installed, flared joints have a high risk of the refrigerant leaking. They can also be easily modified by unqualified persons. Flared joints may be suitable if installed correctly and in accordance with the manufacturer’s installation instructions.
See 6.1.5 Creating flared joints for further information.
29
6.1.3 Maintaining cleanliness of pipework
Ensure that all pipework is clean and suitable for the system by:
• Holding the pipe opening facing down when cutting (Figure 6.11).
• Removing metal filings from inside pipework after cutting.
• Always keeping pipe ends covered with caps, by brazing or taping (Figure 6.12) – covering pipe ends prevents moisture, dirt or foreign matter getting into the pipes, particularly when pushing or pulling through wall cavities.
NOTE: DO NOT let uncapped ends of pipe touch the ground.
6.1.4 Making bends
Bend all copper pipes over 9.5 mm or 3/8" diameter with the correct-sized pipe bender (Figure 6.13) – handmade bends may kink or have a reduced internal pipe dimension, which reduces refrigerant flow and performance.
When pre-insulated pipe is used:• Split the insulation and cut away from
around the pipe.• Bend the pipe using the correct-sized
bender.• Replace the insulation and tape
together using vinyl tape or insert a copper bend using brazed connections, then insulate.
Figure 6.11 Pipe opening facing down when cutting
Figure 6.13 Pipe bender
Figure 6.12 Cover pipe ends
30
6.1.5 Creating flared joints
Flared joints must be formed by an experienced installer, as the joints have a high risk of the refrigerant leaking.
Flaring of joints is not a simple task and requires the correct tool for the refrigerant gas being used and the pipe wall thickness.
Units using R410A, R32 or other high pressure refrigerants require a specific flaring tool to cope with the refrigerant pressure and the pipe thickness.
Follow the correct steps to create a sound flared joint.
Figure 6.14 Cut pipe with tube cutters Figure 6.15 Remove all burrs
• Cut pipe with tube cutters to give a cut that is straight across and clean (Figure 6.14) – use a sharp blade and cut slightly longer than measured length.
• Remember to remove the flare nut from the unit and put it over the pipe end (Figure 6.16) – it is not possible to put it on after flaring the pipe.
Insufficient tube protrusion could lead to a joint that will come apart with vibration and is more likely to leak.
• Remove all burrs with a de-burr tool (Figure 6.15).
• Remove any metal filings that may have fallen into the pipe.
DO NOT use a saw blade to cut the pipe.
• Flare the end of the tube using the correctly-sized flare tool and ensure that the correct amount of pipe protrudes (Figures 6.17 – 6.20).
Excess tube protrusion could stop the flare connection sealing properly when the nut is tightened.
Figure 6.16 Place the flare nut over the pipe end Figure 6.17 Flare the end of the tube (A)
Figure 6.18 Flare the end of the tube (B) Figure 6.19 Flare the end of the tube (C)
31
Figure 6.20 Flare the end of the tube (D)Figure 6.21 Apply oil to the back of the flared pipe and the flare joint
Figure 6.22 Connect the pipes (A) Figure 6.23 Connect the pipes (B)
• Apply oil to the back of the flared pipe and the flare joint. Use oil compatible with the refrigerant before connecting pipes, i.e. use polyolester oil (POE) with R-410A or R32 refrigerant (Figure 6.21). Oil reduces the possibility of tearing the flare when the nut is tightened. Oil must not be allowed to contaminate the refrigerant.
• Hand-fasten the flare nut to connect the pipes (Figures 6.22 and 6.23).
• Tighten the connection using two spanners to the torque recommended by the manufacturer (Figures 6.24 and 6.25) – use a torque spanner to achieve the correct torque. Torque against the second spanner (to secure the load while tightening). Never tighten the connection just against the joint.
Figure 6.24 Tighten connection (A) Figure 6.25 Tighten connection (B)
NOTE:• DO NOT mix polyolester oil and mineral-based oil• DO NOT use leak lock or PTFE tape – these are not plumbing joints• DO NOT cross thread the fittings, as you may damage them.
32
6.1.6 Ensuring pipework is well-supported
Well-supported pipes help ensure the durability and performance of the system by:• reducing the possibility of cracking or oil traps due to sagging• eliminating vibration• eliminating a liquid hammer effect or damage from fluid movement• resulting in better fluid handling characteristics.
As good practice, fix copper tubing at the spacings given in Table 6.1.
Tubing diameter (mm) Maximum fixing spacing (m)
< 6.5 1.0
6.5 – 20 1.5
25 2.0
32 – 40 2.5
> 50 3.0
Source: Australia and New Zealand Refrigerant Handling Code of Practice 2007 clause 5.18.
6.1.7 Insulating refrigerant pipework
• Insulate all refrigerant pipework to improve the efficiency of the heat pump system.• Use a proprietary insulated pair coil, which is heat resistant up to 100oC.
6.1.8 Positioning and connecting the condensate drainage pipe
6.1.8.1 From the indoor unit
Position and connect the condensate drainage pipe from the indoor unit.
• Connect the drainage pipe to the drainage pipe outlet from the unit – if there are two drainage outlets in the condensate tray (indoor unit), connect the drainage pipe to the appropriate side, i.e. to suit the wall outlet location, and insert a rubber bung into the other outlet.
• Wrap the indoor and through wall section of the drainage pipe in polyurethane foam insulation (see 6.1.7 Insulating refrigerant pipework).
• Use smooth, hard PVC-U drainage pipe if drainage pipe runs laterally – flexible, ribbed drainage pipe can be used for vertical drainage.
• Provide sufficient fall for condensate to drain away.• Run the condensate hose beneath the refrigerant line when going through the wall,
to ensure a free flow of condensate.• Connect sections of pipe with pipe solvent – where pipe sizes must be stepped down,
connect sections with silicone sealant internally, then tape around join with vinyl tape.
• Run the indoor drainage pipe:
– to the outdoor unit and drain away to the same location as the outdoor unit condensate
– outdoors to drain onto lawn or garden – discharge into the stormwater system is permitted in some areas (do not discharge into a gully trap).
• Where pipe traps are recommended by the manufacturer to reduce negative pressure, install in accordance with the manufacturer’s specifications.
• Do not allow the condensate outlet pipe to be immersed in water, as this can cause an air lock and prevent water drainage under gravity.
• Use mechanical connectors (jubilee clips) to connect the hoses• Locate indoor units suitably to avoid the need for a condensate pump. Where
unavoidable, install a condensate pump in accordance with the manufacturer’s specification. Advise the owner of the maintenance requirements of the pump and that it may make noise. Failure to do so will void any claim for water damage.
Table 6.1 Fixing spacings for copper tubing
33
NOTE:• DO NOT use flexible drainage piping in internal wall spaces• DO NOT use flexible ribbed drainage piping for lateral pipe runs, as water may sit
in the ribs or low points may occur in the pipe• DO NOT use electrical conduit as a drainage pipe.
6.1.8.2 From the outdoor unit
Discharge condensate: • into a suitable drain connection• onto a grassed or planted area• into a stormwater drain (where permitted by local council regulations).
NOTE: DO NOT discharge where it can run over a footpath as it may become slippery or freeze in winter.
6.2 Pipework pre-installation in new buildings
In a new building, install pipework before wall linings and claddings are put on.
Procedure• Unroll and lay out pipe and connection cable to connect indoor and outdoor units.• Tape pipe and connection cable together with vinyl tape at 1-1.5 m spacings.• Establish the location and centre of the indoor unit.• Establish the location of the outdoor unit.• Run taped pipe/cable across the top of the bottom truss chord/ceiling joist between
the unit locations (Figure 6.26).• Fix with galvanised mild steel pipe brackets.
Indoor unit location• Notch the top plate and studs to a maximum depth of 25 mm (for 90 x 45 mm timber)
or 19mm (for 70 x 45 mm timber) to insert pipe/cable (Figures 6.27 and 6.28).
• Insert pipe/cable into notch and fix galvanised mild steel strap over to hold securely in position (Figure 6.29). Notching and drilling must not exceed the limits given in NZS 3604: 2011– see Figure 4.11. Protect pipe against damage caused by other trades.
Figure 6.26 Run pipe/cable across truss chord/ceiling joist
Figure 6.27 Notch the top plate and studs (A) Figure 6.28 Notch the top plate and studs (B)
34
• Wedge the pipe cable end into the stud in readiness for connection to the indoor unit (Figure 6.30) – use a lightly-fixed and wedged nail that can easily be removed to hold the pipe/cable flat for interior lining fixing.
• Braze pipe ends closed to keep moisture and debris out (Figure 6.31).
Once brazed, pressurize pipework with dry nitrogen. If the pipes get damaged, the gas escapes, alerting other tradespeople to the fact that they have damaged the pipe. If you return and find the gas is gone, then you know pipes have been damaged.
• For floor-mounted units on internal walls:
– fix pipe/cable in notched dwangs
– drill holes and feed the pipes through• Feed pipes through a hole in the
building wrap to outside and seal to weatherproof around pipe.
NOTE: DO NOT cut out more timber than necessary.
Outdoor unit location• Notch the top plate and studs sufficiently to insert pipe/cable. See Figure 4.11 for limits
on notching and drilling framing.• Insert pipe/connection cable and power cable (run from meter board) into notches and
fix galvanised mild steel strap over to hold securely in position (Figure 6.32).
• Feed pipe/cables for connection to outdoor unit through a hole cut in building wrap (Figure 6.33). Installing a sleeve is recommended as shown in Figure 7.4.
• Seal pipes or sleeve with flexible flashing tape to weatherproof around pipework and cables (Figure 6.34).
• Braze pipe ends closed to keep moisture and debris out.• Leave pipe/cable neatly coiled and taped. Note that the taping off has not been
completed in Figure 6.34, nor has a sleeve been used as shown in Figure 7.4.
Figure 6.29 Fix galvanised mild steel strap to hold pipe/cable Figure 6.30 Wedge the pipe cable end into the stud
Figure 6.31 Braze pipe ends closed
Figure 6.32 Fix galvanised mild steel strap to hold pipe/connection cable
Figure 6.33 Feed pipe/cables through building wrap Figure 6.34 Seal pipes or sleeve
35
7.0 Heat pump installationThis section covers good-quality and safe installation of the indoor and outdoor heat pump units, connecting the units to pipework, testing the system for pressure/leaks and evacuation of the system (which must occur after pressure testing).
Some general rules for installing heat pump units are:• follow the manufacturer’s instructions• use tools and equipment appropriate for the task and in a well-maintained condition• ensure components are compatible• keep the entire system clean and dry.
7.1 Pre-installation checklist
Before installing the heat pump units, check the following:
Unit components❏❏ Check that the unit is what was specified and that model numbers match.
❏❏ Remove the unit from the packaging and check that all components are supplied.
❏❏ Check for any damaged components.
❏❏ Ensure that installation and owner manuals are supplied.
Trade co-ordination❏❏ Confirm on-site trade co-ordination between the installer, builder (for new construction) and the electrician (only a registered electrician can hard wire the heat pump units).
Health and safety❏❏ Ensure appropriate health and safety procedures are in place and implemented to comply with the Health and Safety at Work Act 2015 and any other applicable legislation or standards (e.g. electrical safety requirements, flammable refrigerant handling requirements).
❏❏ Appropriately plan the installation including considering the health and safety risks relevant to the installation works, and what steps are required to control those risks before work commences.
Install location❏❏ Check and measure indoor and outdoor locations for available space, access and required clearances for installation and servicing (see 4.7 Step 5: Locate the units).
❏❏ Check the system pipe run does not exceed maximum length and differential height recommended by the manufacturer (Figure 7.1).
❏❏ Confirm the walls are able to provide fixing and support.
❏❏ Identify the location of a suitable power source (see 9.0 Electrical requirements).
36
If max. pipe lengths given as 20 m/12 max. run = 20 m max. height = 12 m
b = max. height
maximum length = a + b
a = max. run
Figure 7.1 Maximum pipe length and height
7.2 Installing the indoor unit
Check the manufacturer’s instructions for minimum clearances – otherwise allow clearances as given in 4.7 Step 5: Locate the units.
• New building:– Locate the pre-installed pipework.
– Have any required dwanging added.
• Existing building:– Locate studs/framing on which to fix the installation plate. Plate should be located
to span across two stud positions.
– Check the structural integrity of the wall.
– Insert dwanging between studs for fixing support if two studs in suitable positions are not available.
• Use a level to check that the installation plate is horizontal before fixing.
• Do not bend the back plate during fixing – if necessary, pack behind.
• For framed walls, screw-fix the installation plate through the wall into the framing behind (Figure 7.2).
• For concrete/concrete masonry walls, bolt-fix the installation plate using anchor or screw bolts.
Figure 7.2 Screw-fix installation plate
37
5 – 7 mm
INDOORS OUTDOORS
framingwall underlay
sleeve with flange tape with flexible flashing tape to wall underlay
65 mm
Figure 7.3 Drill a hole through the wall Figure 7.4 Slope of wall penetration
Figure 7.5 Release the tubing and drainage hose Figure 7.6 Feed the connecting cable through the wall
Figure 7.8 Feed taped bundle through the holeFigure 7.7 Tape tubing, drainage pipe and connecting cable together
• Drill a hole in the wall: Using a 65 mm diameter core drill, drill a hole through the wall to the right or left of the installation plate as required (Figure 7.3). Drill the hole with a slight slope to the outside for drainage (Figure 7.4).
• Attach the indoor unit: Release the tubing and drainage hose from the back of the indoor unit ready for connection to the pipework (Figure 7.5).
• Tape the tubing, drainage hose and the connecting cable together, ensuring that the drainage hose is on the low side of the bundle (Figure 7.7). If you route the drainage hose inside the room, insulate it to prevent condensation forming that may damage furniture or fittings.
• Feed the connecting cable from the outdoor unit through the hole in the wall and connect to the indoor unit (Figure 7.6).
• Check that the wall space is free from electrical cables, plumbing and cross bracings before drilling holes.
• Lift the unit into position and feed the taped bundle through the hole (Figure 7.8).
38
Figure 7.10 Attach unit to wall bracket (B)
Figure 7.13 Expose flared pipe ends
Figure 7.9 Attach unit to wall bracket (A)
• Attach the unit to the wall bracket (Figures 7.9 and 7.10).
Figure 7.12 Taped pipes, drainage pipe and connection cable through holeFigure 7.11 Ensure unit is securely seated
• Ensure that the unit is securely seated (Figure 7.11).
• Fill gaps around the pipe work in the opening formed using a proprietary seal.
• Install cover and face plate to unit. Check that all holes through the wall lining are hidden by the installed unit.
• Feed taped pipes, drainage pipe and connection cable through the hole to the outside (Figure 7.12). Ensure that the condensate drain is at the bottom of the grouped pipes and that there are no kinks in it.
• Remove tape and expose flared pipe ends for connection to copper piping (Figure 7.13) – see 7.4 Connecting piping to indoor and outdoor units.
NOTE: DO NOT use flexible drainage hose inside existing walls unless fully accessible – if it becomes kinked, it may block and cause leakage inside the wall.
39
7.3 Installing the outdoor unit
Install the outdoor unit so that:• it sits level• it cannot fall over• the weight is fully supported to prevent
sagging• it has an unobstructed gap under it
(Figure 7.14)• it creates no vibration• there is a suitable clearance (about
100mm) underneath to allow for hosing and clearing of leaves and dirt
• fixings used are corrosion-resistant – typically requires stainless steel.
The outdoor unit can be fixed on:• a concrete pad cast in place or a single piece pre-cast slab at least 40 mm thick
(see Section 7.3.1)• a concrete patio or balcony (see Section 7.3.2)• a timber slatted deck with anti-vibration mounts (see Section 7.3.3)• brackets fixed to a foundation or wall (see Section 7.3.4)• the roof where the installation has been specifically designed (engineered) to
accommodate live loads and wind forces acting on the roof, and it incorporates anti-vibration mounts (see Section 7.3.5)
• a specified base in accordance with manufacturer’s instructions.
Proprietary mounting systems for roofs and walls are available and should be installed in accordance with the supplier’s instructions.
NOTE: DO NOT fix the unit onto a waterproof deck or a membrane roofing system, as the fixings will penetrate and compromise the waterproofing.
7.3.1 Installing an outdoor unit on a concrete pad
• Construct the pad as shown in Figure 7.15 (check construction if done by others) or place and level a single unit 950 x 450 x 50 mm thick pre-cast concrete slab.
• Fix proprietary mounting rails, where supplied, or hot-dip, galvanised mounting rails at centres to suit the unit.
• Securely fix the mounting rails to the concrete with Grade 316 stainless steel masonry anchors or screw bolts, using two fixings per rail.
• Check that rails are level before tightening – pack with plastic shims as necessary to level.
• Fix the unit to the rails and tighten fixing bolts/anchors.
proprietary footings to provide clearance under unit
fix at centres to suit unit
50 mm
50 mm
50 mm
50 mm
70 mm min. (100 mm) better
concrete pad
Figure 7.14 Unobstructed gap under outdoor unit fixed on concrete pad cast in place
Figure 7.15 Concrete pad construction
40
joists
timber deckinganti-vibration
mounts
fix at centres to suit unit
190 × 45 H3.2 treated timber rails screw-fixed to joists
Figure 7.16 Fixing unit to a timber deck
Figure 7.17 Pack with plastic shims to level
Figure 7.18 Wall-mounted unit on brackets – masonry wall
bracket spacing to suit unit footings
galvanised mild steel brackets bolt-fixed to wall with stainless steel masonry anchors
maintain minimum distance between unit and wall (manufacturer’s recommendation or 150 mm min.)
7.3.2 Installing an outdoor unit on a concrete balcony or patio
• Fix proprietary mounting rails (where supplied) or hot-dip galvanised mounting rails over anti-vibration mounts, at centres to suit the unit.
• Securely fix the mounting rails to the concrete with Grade 316 stainless steel masonry anchors or screw bolts, with two fixings per rail.
• Check that rails are level before tightening – pack with plastic shims as necessary to level.• Fix the unit to the rails and tighten fixing bolts.
NOTE: DO NOT fix units to waterproof concrete or timber-framed decks.
7.3.3 Installing an outdoor unit on a timber deck
• Fix hot-dip galvanised mounting rails into the joists with 75 mm long stainless steel screws. Alternatively, fix the mounting rails to 190 x 45 H3.2 treated timber rails laid on flat that are screw- fixed to the decking joists with 115 mm long stainless steel screws (Figure 7.16). Provide anti-vibration mounts or pads. Fix hot-dip galvanised mounting rails through the rails and joists with 75 mm long stainless steel screws.
• Check that rails are level before tightening – pack with plastic shims as necessary to level (Figure 7.17).
• Fix the unit to the rails and tighten fixing bolts.
7.3.4 Installing an outdoor unit on a foundation or wall (concrete/concrete masonry only)
• Check the structural integrity of the wall or foundation.
• Bolt-fix hot-dip, galvanised brackets or proprietary brackets to the wall or foundation using stainless steel masonry anchors or screw bolts (Figure 7.18).
• Check that the brackets are level before tightening.
• Waterproof around fixings according to the material.
• Fix the unit to the brackets.• Anti-vibration pads may be used.• Ensure the ground underneath is stable,
compact and level• Ensure clearance to ground is sufficient
and as per manufacturer’s instructions.
NOTE: Outdoor units may be able to be wall-mounted to some lightweight claddings but the connections and weatherproofing details must be specifically designed to maintain the integrity of the weatherproofing.
41
7.3.5 Installing an outdoor unit onto the roof
It is not recommended to install a heat pump onto a roof, due to noise vibration transfer, service accessibility, exposure to elements and moisture ingress.
However, if you do, adhere to the following:• Roof installations must be specifically designed.• Always check and follow the instructions of the roofing system manufacturer.• Screw-fix hot-dip, galvanised brackets or a proprietary mounting system into the roof
framing. If mounting on timber base, use painted H3.2 treated timber.• Use anti-vibration mounts.• Insert ethylene propylene diene M-class (EPDM) rubber washers between the bracket
and the roofing.• Check that the brackets are level before tightening.• Seal all fixings as for the rest of the roof fixing; for example, use EPDM or neoprene.• Fix the unit to the base.
NOTE:• DO NOT mount units on concrete or clay tile roofs (tiles are not strong enough to
allow mounting and the weight of the installers working on the roof)
• DO NOT mount directly onto metal roofing, as roofing can act as a sound amplifier and direct fixing may cause corrosion of the roofing
• DO NOT let CCA treated (tanalised) timber come into direct contact with galvanized steel roofing as it is not compatible.
7.4 Connecting piping to indoor and outdoor units
Connection of piping to indoor and outdoor units must be done in the following order:
1. Connect the piping to the indoor unit (see Section 7.4.1).
2. Fix trunking (see Section 7.4.2).
3. Connect the piping to the outdoor unit (see Section 7.4.3).
7.4.1 Connect the piping to the indoor unit
• Use twin-insulated and dehydrated copper piping.
• Cut and flare the copper pipes for connection to the indoor unit (see 6.1.5 Creating flared joints).
• Apply oil to both the flare and the indoor unit, ensuring that the oil is compatible with the refrigerant.
• Align and connect the pipes and tighten the flare nut by hand.
• Tighten the flare nut connections using two spanners to the correct torque.• Overlap the connection pipe and indoor pipe insulation.• Bind the insulation with foam insulation tape, then follow with vinyl tape (Figure 7.19).
• Connect and tape the drainage hose to the drainage outlet (Figure 7.20).
Figure 7.20 Tape drainage hose to drainage outlet
Figure 7.19 Bind insulation with vinyl tape
42
7.4.2 Fix trunking
• Screw-fix proprietary trunking to the exterior wall from the outlet to the outdoor unit.
• Use stainless steel screws.• Install trunking neatly in straight runs
with 90º angles, tight weather seals and waterproof flashings (Figure 7.21).
• Run horizontal trunking with a slight downhill slope if it contains the condensate drainage pipe.
NOTE: For aesthetic reasons, minimize the use of trunking indoors.
• Fit refrigerant piping, drainage pipe and connecting cable into trunking (Figure 7.22).
• Attach trunking cover.
Figure 7.21 Install trunking neatly
Figure 7.22 Fit refrigerant piping, drainage pipe and connecting cable into trunking
Figure 7.23 Fill hole around piping with sealant
Figure 7.24 Seal around cover
Figure 7.25 Fit cover over opening
• Fill hole around piping with sealant compatible with the trunking and the cladding system (Figure 7.23).
• Seal around and fit cover over opening (Figures 7.24 and 7.25).
43
7.4.3 Connect the piping to the outdoor unit
• Cut both pipes to the correct length.• Flare the pipe ends for connection to
the outdoor unit (see 6.1.5 Creating flared joints).
• Purge the system by blowing oxygen- free nitrogen (OFN) into the pipes before making final flare connection. Note: Hard-drawn copper pipe must be annealed before bending and therefore also requires purging with nitrogen.
• Apply oil to the front and back face of the flare and the outdoor unit, ensuring that the oil is compatible with the refrigerant (Figure 7.26).
NOTE: DO NOT use adhesive threadlocker or thread sealant.
• Align and connect the pipes and tighten the flare nut by hand (Figure 7.27).
• Tighten the flare nut connections using two spanners and to the correct torque (Figure 7.28).
• Check all mechanical joints for tightness on completion.
• Remove all rubbish from the installation.
• Clean any marks from the area around the units.
Figure 7.26 Apply oil to the back of the flare and the outdoor unit
Figure 7.27 Connect pipes and tighten flare nut
Figure 7.28 Tighten flare nut connections
44
Figure 7.29 Remove vacuum pump and gauges (A)
7.5 Leak/pressure test
It is good practice to pressure test the system for leaks after completion of pipework installation. Test in accordance with the methods specified in the Australia and New Zealand Refrigerant Handling Code of Practice 2007, Part 1: paragraphs 3.2.1 and 3.2.2.
Procedure• Remove the service port valve cap from the gas valve on the outdoor unit (the
isolation valve must be kept closed).• Use oxygen-free dry nitrogen (OFN). Any oxygen introduced into a system during
pressure testing can be extremely dangerous and can cause a large explosion.• Connect the nitrogen gas cylinder to the service port valve.• Pressurise the system to maximum 500 psi/3.45 MPa and allow to hold for 5 minutes.• Watch the pressure gauge for any drop-off in pressure.• Test joints by using a bubble test solution. If using electronic testing, a trace gas must be
added to the nitrogen. Electronic testing can be unreliable in windy conditions – if a leak is found with an electronic tester, it must be verified using a bubble test solution.
• Release the nitrogen pressure to discharge.• Disconnect the cylinder when the pressure has returned to normal.• Wipe the bubble test solution off the joints after testing.
7.6 Evacuation of the system
It essential that you evacuate the system to remove air, moisture and any nitrogen remaining from the pressure testing. Any air, moisture or foreign matter remaining in the system may cause:• the pressure in the system to rise, resulting in compressor malfunction• the operating current to rise, resulting in performance loss• moisture to freeze and block pipework and valves• oil sludge build-up• corrosion of parts of the system.
Always use an electronic digital vacuum gauge to monitor the evacuation.
Ensure as a minimum, that the vacuum pump is in good working order, is serviced regularly and has clean oil. Vacuum pump oil should be replaced after 25 uses or every 6 weeks. Ensure the vacuum pump is equipped with a backflow prevention device to prevent the oil in the pump flowing backwards into the refrigerant pipes (should power fail during the test) as this could cause major damage to the system.
ProcedureCarry out the evacuation according to:• the manufacturer’s instructions, or
• the methods specified in the Australia and New Zealand Refrigerant Handling Code of Practice 2007, Section 6.
• Connect the vacuum pump hose to the service port valve on the gas valve.
• Start the pump.
• Evacuate to 200 microns measure with an electronic vacuum gauge. The evacuation time will vary according to the pump capacity and the length of the tubing. Moisture removal will occur in the evacuation process when the pressure is 500 microns or less. Read the gauge for a pressure reading to check evacuation – do not time.
45
• When the required level of evacuation has been reached, close the manifold valve and stop the pump.
• Allow to hold for minimum 10 minutes – refer back to 7.5 Leak/pressure test if pressure not held.
• Remove the vacuum pump and gauges (Figures 7.29 – 7.31).
• Progressively release the vacuum by opening both the liquid and gas side isolation valves. Use the valve core removal tool and turn it counter-clockwise a ¼ turn (Figure 7.32) so that air is not introduced into the system.
• Replace both liquid and gas valve caps and gas service port valve caps and tighten using an adjustable wrench (Figure 7.33). If a valve cap cannot be finger-tightened first, do not force- tighten it, as this may strip the thread. Instead, remove and refit the cap. Securely fasten the caps to prevent refrigerant leakage from the system. – Leak test with bubble solution to confirm.
Figure 7.30 Remove vacuum pump and gauges (B)
Figure 7.32 Progressively release the vacuum
Figure 7.33 Tighten valve caps
Figure 7.31 Remove vacuum pump and gauges (C)
46
8.0 Refrigerants A number of different refrigerants have been used over the years and all have some degree of impact to the environment.
It is important to minimise refrigerant leaks because they can damage the ozone layer, increase greenhouse gases or present health and safety risks.
Early refrigerants used were chlorofluorocarbons (CFCs), but the ozone-depleting nature of these compounds has led to them being phased out and replaced with hydrochlorofluorocarbon (HCFC) compounds such as R-22. For environmental reasons HCFCs have also been phased out and replaced with blended hydrofluorocarbon (HFC) compounds.
Hydrofluorocarbons (HFCs) such as R410A and R32 are currently widely used in refrigeration and air conditioning systems. However, HFCs are greenhouse gases with high global warming potential. A worldwide phase down of HFCs is being implemented from 2019.
The switch from HFCs to more environmentally acceptable alternatives will help combat climate change, but will also present increased risks to health and safety in some circumstances because of the higher toxicity, flammability or pressure of common alternatives.
When purchasing a heat pump, ensure you understand which refrigerant is suitable for the system. The installation and technical guide supplied by the manufacturer will provide this information and must be observed at all times.
NOTE: DO NOT use the incorrect refrigerant in a heat pump as this could void the warranty and can create the risk of an accident.
Australia and New Zealand Refrigerant Handling Code of Practice
Fluorocarbon Refrigerants
Compliance with the Australia and New Zealand Refrigerant Handling Code of Practice 2007 is mandatory for the handling of fluorocarbon refrigerants by anyone holding a refrigerant handling license or refrigerant trading authorisation. The Code of Practice is in two parts:
• Part 1 covers self-contained low charge systems that do not require any work on the refrigeration circuit to install and contain less than 2 kilograms of fluorocarbon refrigerant.
• Part 2 covers all other stationary and transport refrigeration and air conditioning systems.
Essential requirements of the code are that:• heat pump systems must be able to be installed, operated, serviced and
decommissioned without loss of refrigerant• heat pump systems must be installed by an appropriately qualified person with
Approved Filler Compliance Certificate for refrigerant handling.• refrigerant must not be intentionally released into the atmosphere. Releasing
refrigerants into the atmosphere can incur hefty fines.
NOTE:• ALWAYS check with the manufacturer for the correct refrigerant to be used• ALWAYS confirm with your local authority, industry association, or the
manufacturer to ensure the installer is suitably qualified• DO NOT use an unqualified, uncertified installer.
47
8.1 Refrigerant charging
The outdoor unit is factory-charged with sufficient refrigerant to allow for the indoor unit and a specific pipe run. Refer to the manufacturer’s installation instructions for the pre-charge pipe length.
You will need to add extra refrigerant where pipe runs exceed the manufacturer’s parameters for the factory-charged amount of refrigerant.
You must carry out refrigerant charging in accordance with AS/NZS 5149:2016 Part 4 Operation, maintenance, repair and recovery.
Procedure• Only use the refrigerant specified by the manufacturer for charging.• Measure the additional pipe run length.• Accurately calculate the amount of refrigerant required according to the
manufacturer’s instructions.• Measure the required amount of refrigerant (where additional charge is required) by
mass, using electronic scales.• Keep the charge lines as short as possible.• Leak test the pipework before charging, by partially opening, then closing the cylinder
valve to pressurise the connecting pipework.• Charge using liquid refrigerant from the cylinder.• Check for leaks using the bubble test solution.• Ensure that the cylinder and unit are at the same height to prevent gravity transfer of
the refrigerant.
NOTE:• DO NOT release refrigerant into the atmosphere. Releasing refrigerants into the
atmosphere can incur hefty fines• DO NOT use ultraviolet dye• DO NOT use reclaimed refrigerant to add additional charge.
8.2 Labelling as record of service
You must label any system that is charged with refrigerant or lubricant. Label compressors, systems and liquid refrigerant pumps in accordance with AS/NZS 5149.2: 2016 clause 4.5 marking and documentation.
Place a permanent label on the outer side of unit that identifies:• refrigerant type• date of service• lubricant type• refrigerant charge (total including any additional charge).
48
9.0 Electrical requirementsThis section covers electrical requirements for heat pump installations.
All electrical work must be carried out by a registered electrician. An Electrical Certificate of Compliance (CoC) must be issued on completion.
Electrical work must be carried out in accordance with the Electricity Act, Electricity (Safety) Regulations, including the cited edition of AS/NZS 3000 Electrical installations (known as the Australian/New Zealand Wiring Rules).
9.1 Installing electrical wiring
Depending on the heat pump’s power input rating and the building’s existing electrical installation, the heat pump may either be connected to an existing electrical circuit with sufficient spare capacity (e.g. looped off an existing power socket), or to a separate dedicated circuit (wired back to the main switchboard).
• Select a circuit for the main power supply.• For installations in new buildings, use a dedicated circuit.• Refer to the manufacturer’s specifications for:
– rated voltage
– input capacity/fuse size
– electrical cable size
– wiring diagram for electrical installation.• All hard wiring must be carried out by a registered electrician.
9.2 Outdoor unit connections
• Remove service cover from outdoor unit.• Fix indoor/outdoor connecting cable
correctly to the terminal block in the outdoor unit.
• Tighten terminal screws to ensure that wires are firmly secured.
• Connect power supply cable to terminal block in outdoor unit (Figure 9.1).
• Install a lockable isolating switch (Figures 9.2 – 9.4).
• Install the switch so that it can be reached for servicing
• Attach the isolating switch to the house – not the outdoor unit.
NOTE: It is an offence to mount a switch on the unit.
Figure 9.1 Connect power supply cable to terminal block
Figure 9.2 Install lockable isolating switch (A)
49
• Provide waterproof protection to the connection as required, such as:
– cable gland
– flexible conduit.
• Replace service cover to outdoor unit when all connections are completed (Figure 9.5).
NOTE:• DO NOT connect the isolating switch to the outdoor unit. Otherwise the unit
cannot be isolated from power• DO NOT allow contact between wiring and refrigerant pipework• DO NOT run the main power cable and heat pump system power cable together• DO NOT allow electrical work to be carried out by an unlicensed tradesperson
or without an Electrical Certificate of Compliance (CoC). Otherwise, the owner’s house insurance may be voided.
9.3 Nameplate
Ensure nameplate (Figure 9.6) is visible in an accessible location displaying:
• manufacturer’s name and/or trademark• type or model designation and serial
number• rated voltage• rated frequency• cooling capacity• heating capacity• refrigerant type (designation) and charge.
Figure 9.3 Install lockable isolating switch (B)
Figure 9.4 Install lockable isolating switch (C)
Figure 9.5 Replace service cover to outdoor unit
Figure 9.6 Example of a nameplate on an outdoor unit
50
10.0 Testing, commissioning and customer operating instructionsThis section covers what you need to do once a heat pump system is installed. It includes what to check before it is commissioned, testing the system, briefing the homeowner on the new system and carrying out a quality assurance check once everything is completed.
For testing and commissioning, follow manufacturer’s instructions where provided; otherwise follow the Australia and New Zealand Refrigerant Handling Code of Practice 2007.
10.1 Pre-commissioning checks
Outdoor unit – check:❏❏ The unit is secure and correctly mounted.
❏❏ There is a clear air movement path.
❏❏ Ensure the valves are fully opened and valve caps have been replaced and securely tightened.
Indoor unit – check:❏❏ Unit mounting is level and secure.
❏❏ Remote control base is securely screwed to wall.
Pipework – check:❏❏ Pipework has been correctly installed and secured.
❏❏ Pipework is correctly insulated.
Indoor unit drainage – check:❏❏ Pour some water into the indoor unit drainage pan. Ensure that the water flows through the outlet and drainage hose without leaking.
❏❏ If a condensate pump has been used, test this is working correctly, that it is not siphoning, and that the float switch is working correctly.
10.2 Electrical checks
Wiring: ❏❏ Carry out tests required under the Electricity (Safety) Regulations, including the cited edition of AS/NZS 3000 Electrical installations (known as the Australian/ New Zealand Wiring Rules).
❏❏ Electrical code compliance certificate is obtained and a copy handed to the owner.
Labelling:❏❏ Ensure Switchboard fuse has been labelled appropriately
10.3 Prepare the remote control
❏❏ Remove the battery cover.
❏❏ Insert new batteries.
❏❏ Replace cover.
51
10.4 Testing the new system
❏❏ Switch the system on.
❏❏ Ensure that no LED lights are on. If LED lights are on or blinking, the installation is faulty. Refer to unit handbook to identify fault as indicated by flashing LEDs. Then disconnect the power supply and locate and fix the fault.
❏❏ Check the emergency operation by pressing the emergency operation on/off switch and holding down for 3-5 seconds. This will start a test run (continuous operation for a set period) during which the thermostat does not work.
❏❏ Press the emergency operation on/off switch again to turn off.
❏❏ Test unit in heating and cooling mode, as described below.
Indoor unit – check:❏❏ The fan operates at all speeds.
❏❏ There is no vibration of the unit.
❏❏ Vertical and horizontal air direction controls are operating.
❏❏ Air circulation mode (circulating air without heating/cooling) is operating.
❏❏ The unit operates to the correct heat command – use a thermometer. With an indoor ambient air temperature of 21°C:
– for heating, an air-off coil temperature of 45-50°C or higher should be achieved
– for cooling, an air-off coil temperature of 8-12°C or lower should be achieved.
❏❏ The manual operation (using the switches on the indoor unit) is functioning – for situations when the remote cannot be used.
❏❏ The auto start is functioning.
❏❏ An electronic sound can be heard by pressing the on/off button of the remote control.
❏❏ The condensate pump (if installed) works.
10.5 Instructions to the owner
Checklist of instructions to the owner on the use of the system:❏❏ Demonstrate how to set the controls/different modes correctly.
❏❏ Demonstrate how to use the remote control.
❏❏ Demonstrate how to remove and clean air filters.
Advise:
– on what to expect in extremely hot or cold conditions
– that the system will take a few minutes to warm up
– consider turning the heat pump off late at night if the noise bothers the neighbours.
❏❏ Advise of service requirements.
❏❏ Recommend reading the operating instructions manual.
❏❏ Provide a service checklist.
❏❏ Provide the warranty.
Before the installer leaves❏❏ Electrician to provide an electrical Certificate of Compliance (CoC).
❏❏ Provide a record of the system commissioning data.
❏❏ Provide contact names and numbers for after sales support.
52
10.6 Checklist for using a heat pump efficiently
Understanding how to use a heat pump efficiently is important information for users.
• Only heat when you need it - don't leave your heat pump on all day if you're not there. Use the timer to turn on the heat pump shortly before you get home and turn it off when you don’t need it.
• Set the thermostat to a healthy temperature - aim for 18ºC to 21ºC. High thermostat settings cause high electricity use. Inadequate heating can lead to mould growth and dampness.
• Avoid using the 'Auto' mode - use the 'Heating' mode. In 'Auto' mode, the heat pump tries to maintain the set temperature by constantly changing between heating and cooling, as the room temperature fluctuates. This can waste a lot of energy.
• Avoid the ‘Low’ and ‘Quiet’ Fan settings during very cold weather. To get the full heating power out of your heat pump, choose the ‘Auto’ Fan setting.
• It is normal for the heat pump to sometimes stop heating or blow out cold air during very cold weather, while the outdoor unit defrosts. This usually only takes a few minutes. Contact the manufacturer if you have any concerns.
• Clean the filter regularly (as often as monthly) - this is a quick, easy job you can do yourself. Clogged heat pump filters mean the heater uses more power to run.
• Avoid using it as an air conditioner when you can - try opening windows and doors on either side of the house to create a through-breeze. Close curtains on hot, sunny days to keep your home cool and shady.
More information is available on www.eeca.govt.nz
53
10.7 Quality assurance checklist
Carry out a quality assurance check on completion of the heat pump installation pump system.
Outdoor unit❏❏ Is the outdoor unit secure with no likelihood of falling over?
❏❏ Is there any vibration or noise disturbance to owners and/or adjacent properties?
❏❏ Is the area around the unit clear so there is no likelihood that the air supply routes will become blocked?
❏❏ Has the unit been installed to provide future servicing access?
❏❏ Is all the exterior ducting neat and tidy, with all flashing and waterproofing completed?
❏❏ Have all service covers been replaced?
❏❏ Is the unit clearly labelled?
❏❏ Have the installer’s checklists been sighted?
Indoor unit❏❏ Is the indoor unit secure and does it not vibrate?
❏❏ Has the test run been carried out?
❏❏ Is the unit neatly installed with no pipework or ducting visible?
❏❏ Have the installer’s checklists been sighted?
Pipework❏❏ Is the pipework appropriate for the refrigerant used in the system?
❏❏ Has a leak test been carried out?
❏❏ Was the system evacuated?
❏❏ Is the system charged to a level appropriate for the pipe length?
❏❏ Are the stop valves fully open?
❏❏ Have the installer’s checklists been sighted?
Drainage❏❏ Is the drain hose from the indoor unit properly installed?
❏❏ Has the indoor unit drainage been tested by pouring water into the tray?
❏❏ Has the outdoor drainage pipe been directed away appropriately?
Electrical❏❏ Does the electrical work have an electrical Certificate of Compliance?
❏❏ Has a copy of the electrical Certificate of Compliance been given to the owner?
❏❏ Is the unit connected to a separate circuit, hard wired back to the mains distribution board (or if connected to existing circuit, does it have sufficient spare capacity)?
❏❏ Is there a circuit breaker in the system and has the circuit been properly labelled on the distribution board?
❏❏ Is the energy rating label on the unit or available for viewing?
Instructions to the owner❏❏ Has the operation of the system been explained to the owner?
❏❏ Does the owner have the operating manual?
❏❏ Has the owner been advised of maintenance and servicing requirements?
❏❏ Does the indoor unit have the energy rating label applied, or available?
❏❏ Has the owner been given a copy of the warranty?
54
11.0 Servicing and maintenanceIn addition to regular maintenance by the owner, it is recommended that a routine maintenance agreement is put in place with a licensed service person or organisation. In addition, users should monitor their heat pump and call a service person immediately if any abnormal operation is found.
11.1 Owner maintenance
Follow manufacturer’s instructions. Most manufacturers provide copies of their manuals on their website.
Indoor unit❏❏ Check air filters of the indoor unit every 3 months’ use and clean or replace as necessary (some units will identify when filters need cleaning or be self-cleaning).
If they can be cleaned:
– remove and vacuum clean using a brush attachment then replace, or
– wash gently with a mild detergent and warm water, and dry before replacing.
❏❏ Check the indoor coils (if accessible) – dust gently with a soft brush to clean.
❏❏ Check and clean condensate pan, drain and trap.
❏❏ Clean the unit cover with a damp cloth and mild detergent as required.
❏❏ Recognise the operational sound of the heat pump – if the sound changes, have the system checked.
❏❏ Ensure that air vents are not blocked by furniture or objects.
❏❏ Check operation of condensate pump every 6 months (if fitted).
NOTE: DO NOT vacuum the indoor coil fins as they are easily damaged.
Outdoor unit❏❏ Keep the area around the outdoor unit clear of garden waste and dirt.
❏❏ Remove any growth around or into the unit.
❏❏ Make sure the unit is off when cleaning. Follow manufacturer’s instructions when turning off the power.
❏❏ Check and clean the outdoor coils as per manufacturer’s instructions when they are dirty. In a corrosive environment cleaning may be required as regularly as every 3 months. Do not spray the fan motor or wires with water.
❏❏ Contact a service person at any sign of unusual sounds or operation.
❏❏ It is recommended to have an annual servicing agreement with your installer. Failure to maintain your heat pump to the manufacturer’s instruction may void the warranty.
NOTE: DO NOT spray the fan motor or wires with water.
55
11.2 Service person maintenance
The system should be serviced by a qualified person every 12 months, depending on use. Before servicing, establish the type of refrigerant used in the system.
Indoor unit❏❏ Inspect the filters, blower and indoor coil for dirt or obstructions. Clean these parts with a biodegradable cleaner.
❏❏ Check the airflow.
Outdoor unit❏❏ Clean the condenser coils as follows:
– Clear the outside of the coil of debris.
– Vacuum the coil fins using a soft bristle brush attachment – take care to avoid bending the fins.
– Spray water from the inside to the outside of the coils to remove stuck debris using a hose and spray gun. Do not spray the fan motor or wires with water.
– Vacuum or remove by hand any debris remaining in the unit.
❏❏ Check coil fins for damage – if coil fins are bent, straighten using a proprietary tool.
❏❏ Lubricate fan bearings if required – sealed bearing units do not require lubricating.
❏❏ Inspect fan for damage and repair as required.
❏❏ Replace grille covers.
❏❏ Check that the condenser unit is secure and level in both directions. If necessary, adjust the levelling feet, or make level with timber/plastic shims. If the unit is seriously out of level, repair or replace the base the unit sits on.
NOTE: DO NOT spray the fan motor or wires with water.
Refrigerant❏❏ Check the indoor unit output temperature with a digital thermometer. At an indoor ambient air temperature of 21°C:
– for heating, an air-off coil temperature of 45-50°C or higher should be achieved
– for cooling, an air-off coil temperature of 8-12°C or lower should be achieved.
❏❏ Check pipe joints for refrigerant leakage with bubble solution.
Electrical❏❏ Check terminals and connections – clean and tighten if necessary.
❏❏ Check fan motors for lubrication.
❏❏ Check that all controls are operating correctly.
❏❏ Check that the thermostat is operating correctly.
❏❏ Check the voltage.
Service checklist❏❏ Provide the owner with a service checklist after each service.
Level 8 · 44 The Terrace · PO Box 388 Wellington · New Zealand
P: +64 4 470 2200 · F: +64 4 499 5330
www.eeca.govt.nz
EECA, Energy Efficiency and Conservation Authority, own the intellectual property rights in our trade marks and
copyright featured in these guidelines.
© EECA Energy Efficiency and Conservation Authority 2019.
EEC0312 / APRIL2020
